#include <cstdio>
#include <algorithm>

using namespace std;

const int maxn = 10005;

int n, head[maxn], cnt, depth[maxn];

struct _edge {
	int v, next;
} g[maxn << 1];

inline int iread() {
	int f = 1, x = 0; char ch = getchar();
	for(; ch < '0' || ch > '9'; ch = getchar()) f = ch == '-' ? -1 : 1;
	for(; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
	return f * x;
}

inline void add(int u, int v) {
	g[cnt] = (_edge) {v, head[u]};
	head[u] = cnt++;
}

void dfs(int x, int f, int d) {
	depth[x] = d;
	for(int i = head[x]; ~i; i = g[i].next) if(g[i].v ^ f) dfs(g[i].v, x, d + 1);
}

int main() {
	n = iread();
	for(int i = 1; i <= n; i++) head[i] = -1;
	for(int i = 1; i < n; i++) {
		int x = iread(), y = iread();
		add(x, y); add(y, x);
	}

	dfs(1, 0, 0);
	int id = -1, ans = -1;
	for(int i = 1; i <= n; i++) if(depth[i] > ans) ans = depth[i], id = i;
	dfs(id, 0, 0);
	for(int i = 1; i <= n; i++) ans = max(ans, depth[i]);

	printf("%d\n", ans);
	return 0;
}
